We'll keep updating this as more manufacturers make ready their 45 degree, and 45/90 compatible receivers.

The difference between a strictly 45 degree selector compatible receiver, and a 45/90 compatible receiver is the FIRE/pictogram position. A 45 degree only receiver's FIRE/pictogram engraving is close to 60 degrees, which allows the 45 degree's position indicator to point at it when the selector is set on FIRE. A 45/90 compatible receiver's FIRE/pictogram engraving is situated at 68 degrees, thereby allowing both the 45 and 90 degree selector to both point to its general direction when the selector is switched to FIRE.